Method of and apparatus foe testing



C. .J. KROGEL Feb. 6, 1945.

2,368,763 METHOD OF AND APPARATUS FOR TESTING COVERS ON CORES ATTORNEYI- w N MM mm; mm 5 v9 1 w R a 8 at V. a 2 4 9 l l V. l H J d e l 1- F MlIL vw E bx r R Patented Feb. 6, 1945 UNITED STATES PATENT OFFICE OF ANDAPPARATUS FOR TESTING COVERS N CORES Christopher J. Krogel, Cranford, N.J., assignor to Western Electric Company, Incorporated, New York, N. Y.,a corporation of New York Application July 1, 1942, Serial No. 449,284

12 Claims.

tors in some instances through diesof different types and it isimportant that during the application of one insulating cover to theconductor,

that the preceding cover or covers be sufficiently tight upon theconductor to withstand the drag thereon applied in passing through suchdies.

Objects of the invention are to provide a simple, eflicient and highlypractical method of and apparatus for testing the tightness of a covermgon a core. 1

With these and other object in view, the invention comprises anapparatus by the aid of which the method may bepractised for elongat inga covered core a measured distance proportional to the original lengthof the core, and

determining the tightness of the cover on the.

core subsequent to the elongation of the latter.

Othe objects and advantages-will be apparent from the following detaileddescription when considered in conjunction with the accompanyingdrawing, wherein Fig. 1 is a front elevational view of the apparatus bythe aid of which the method may be practised; H

Fig. 2 is a vertical sectional view taken along the line 22 of Fig. 1;

v Fig. 3 is a vertical sectional view taken'along the line 3--3 of Fig.1; I

Fig. 4' is a view of a covered coreprior to the test, and .7

Fig. 5 is a view of the covered core after the test.

Referring now to Figs. 1 .to 3 inclusive the;

apparatus comprises a table. II! having a. stationary unit, indicatedgenerally at H, mounted at one end thereof and a movable unit, indicatedgenerally at l2, disposed at the other end thereof. The stationary unitincludes a base ortion l4 fixedly mounted upon thetable l0 and aperturedat l5 to receive, by a force fit, a pin IS. A scale l1, graduated .as"at I8 in fractions upper graduated edge disposed adjacent an uppersurface [9 of the base. A clamping jaw 20, having a lower surfaceZlparallel with the surface IQ of the base, isprovided with an aperture22 for a sliding vertical movement onithe pin l6 and is adapted formovement toward the base bya clamping screw 23, the threaded end of thelatter being eceivable in. a threaded aperture 24 of the base. Y 1 lAttention is now directedto the movable unit 12, which has. aclamping'jaw 25; substantially identical in structure to the clampingjaw 20 and is mounted for movement on a pin 26, the lattebeing'receivable in an aperture 21 of the jaw. The pin 26 is rigidlymounted in an aperture 28 of a base member 29, the latter also having athreadedaperture 30 therein to receive the threaded end of a clampingscrew 3| serving toforce the jaw 25 toward the base for a purposehereinafter described. 'As will be observed by viewing Fig. 3, the base29 has laterally projecting tongue ortions 32 slidable in grooves 33formed by a main groove 34, in a stationary support 35, and thecooperation of" plates 36 mounted upon the upper surfaces of thesupport. Thus the unit I2 is supported for a direct line movement on thesupport 35. A stop 31 limits the forward movement of the unit, the stopbeing mounted uponthe support 35.

It will be observed that the support is rigidly mounted upon the tableIll. and has a scale mounted thereon and extending from the adjacentsurface of the stop, which is the normal starting position. of the unit[2, to the opposite of an inch, is mounted upon the base 14 with its 63end or limit of movement of the unit, the scale being provided withgraduations 4| representing fractions of an inch. At the farthest orright end of the support 35, vertical projections 42 provide bearingsfor a shaft 43 upon the forward end of which is mounted'a crank 44.Between the projections 42 and mounted upon the shaft 43, is a drum 45to which is secured one end of a cable 46, the cable being given anumber of turns about the drum andex-tended to an integral verticalportion 41 of. thebase-29, to which it is secured as illustrated in.Fig. The drum..45 has integral ratchet teeth 48 which a :pawl 49 isadapted to engagefto'lock the drum at any desired position, the pawl"being pivotally supported on a pin 50 carried by theadjacent'projection 42. f

Through the aid of this apparatus themethod may be practised totest'thetightness of a cover on a core. By selecting the covered core 5|illustrated in Fig. 4, the cover 52 being removed from the ends of thecore so that these ends cover is free on the core, then it is known thatof the core may be clamped, leaving the cover the materialtested willnot withstand the next free of the clamping means, one end of the coreprocessing step. However, if the cover remains is clamped between thejaw 20 and the base M tight upon the'core it is known that the materialof the stationary unit H and is so positioned from which the sample wastaken will withstand therein that the adjacent end of the cover is thenext processing step.

in engagement with the right hand surface of To, determine the exacttightness of v the cover the unit to register .withwthe first marking onon the coreythe' operator may continue the elonthe scale H. The otherend of the core may be gation 'of the core at a' reasonably slow speedclamped, as illustrated in Fig. l, with the bare 1,0, and simultaneouslytest the cover until the time end of the core between the jaw 25 and thebase when the cover is free on the core. At this time 29 and theadjacent end Qfth eovere theelongating'prooess may be stopped, the uniting the unit at a position in registration with L2 beingheld at thatposition by the pawl 49 the end of the scale 40. In other words, asamand its ratchetteeth 48, after which the measureple covered core istaken from a supply which 5 ments'may be taken from the scales l1 and40, is to be tested and prepared'so, that the length, th total of which,when divided by the number of the "Core under the Cover, and naturallythe of the inches representing the original length of length of e Veequal the'distance between the core, will give the percentage ofelongation the inner surfaces of the un ts when in the posinecessary tofree the cover from the core. Theretion shown in Fig. 1, so that theends of the cover fore, as the tightness of the cover on the core willsresister with the beginning e s f is measured by-thez percentage" of.elongation of scalesiand, relative, movement'of the units, after thecore necessary for freeing the cover theret u cove d n s hetVe b clampedin p from through this method: theltightness of: the

will efiect elon ationiof ,the core which is orig-j coveron the coremay' bevreadily' determined inallywithin the cover; through theelongation of the corewa-givenlength The next step Oft ed is to C uelOne proportional tothe .originallengthwof the covered gationof -thecore a predetermined distance, this core under test. I Furthermore, anypercentage;

dis an depending p ihe length 'O the of elongation off the covered core,and as the-- covered core and the distance requiredv to detertightness:of; the: cover is determined by the mine-satisfactorily the'tighfinese0f the cover On 30 necessary percentage: of elongation to loosen it;

the core as well as theknown. percentage of may be-determmedzthrough-theaid:of the method elongation; of the-material, of which the core is a dapparatus; v

formed; prior to breakage thereof. In the present Although specificimprovements 0:- the inveninstancethe coreis formed of copper and thetion.- have been'shown andq'deseribed; it will be breakegepoini? pp r pe o ti n is p- 5=understood that they arebutl illustrative and that:proximately twenty-eight per cent (28%). By various modificationsmaybe'made therein with this it is. meant that a given length (one hunoutdeparting from: the-.scopeand spirit of this dred' inches) of copperwire elongated twenty' 9 inventionas;define.d.bytheappendd claims; eightperv cent (toone hundred twenty-eight What; is claimed is:.- I v 1inches) will-at that po t br that b i g t e 40 l. A. -method1 oftesting. a coveredcore, the ext t o ation of: Copper" be ore it breaks.cover thereof-adhering toy-the core, comprising However, theimportantproblem forconsideraelongating the core; of a-covered core of'agiven tion is to-determinethe tightness of the insulata I length, to apredetermined additionall'ength; and ing materialon thecorein proportionto the de subsequently;applying-aforcesto the coverlongigreeof-el'ongationtowhich the'core'will be sub tudinallylof thecoveratordeterminei whether orjetted in passing through a subsequentstep of not-th cover remainsaadheredito thecore;

a cover-ingprocessw w l 2..A: metho.d of testing a coveredcore, the -Intheproee g of such Conductors they are cover thereof'adhering: to thecore, comprising-- drawn through. the necessary parts of theelongating-the core, of acovered core'of'a given processing machines-andif it is known that there 1 fifllength, to -a measuredladditionallength;and-subwill:be,'for example, a threeper cent: (3%) clone; sequentlyvapplying-au-forcerto the cover longitugation of the core in passingthrough a. subsedinally of the-cover to determine whether orq floperation, itisthenio y ecess y v v not. the cover remainszadhered tothe core;

to subject the coveredxcore toa test substan- 3. A method of testing acovered: core; the

tially equalor slightly greater than the three 5:5, cover thereof.adheringwto the: core, comprising per cent: (3%.) elongation. Thismaybe-readily elongating the core: of a'covered core of agivenaccomplishedlby the-operator rotating the crank length, measuring theamount of elongationof 44 with itsshaft 43:1in a clockwisedirection,viewthe core: during the-elongation thereof, stopping ing at'thesame-time thescaleszt'fli and 49511111211 the elongation of thecorewhenthe core-has thereappeanbetween-the ends of-the cover andgo-been elongated to a predetermined length, and the respective ends ofth units l I: and I2; unsubsequently applying a force to the coverlongicoveredportions of the core of length which. tudinally of" thecover to determine whether or equal the. desired percentage: of: thetotal length not the cover remains adhered to the core.

of-the covered cores- Eor example, ifthecovered 4. A method of testing acovered core, the

portion ofi'the cor :.,under.-test shoulcl'be. twenty cover thereofadhering to the core, comprising" inches. in length anclthe operatorwishes to cause elongating the core'oi a: covered'core of a" given anelongatiomoi the core v-withinrvthe cover five;

length, measuring the'amoun-t of'elongati'on of per: cent (5%.), the;operator-could watch the the coreduring the elongati'on thereof,stopping scales during, therotation of the; crank and shaft,theelongation of the: c'orewhen the-core has resultingjn the movementofthe unit l2 through Tot-been elongated to apredetermined lengthholdthe cable 46 until the total elongation illustratedl ing the core intheelongated position; and sub' by the; bare:coreportionsjappearing-adjacentthe sequentlyvapplying a: force to thecover Iongitu a sequal one n n n-i neth. l 1 dinally oi the coventodetermine whether or I At thi 'i met p r may t st the eov i notzthe;coverremams raclhei -edito the 'core on the -corenby attempt ngl'omovetit. Ii-thmNa-li ,:5.,Armethod: ofztestingaucoveredt core, the

cover thereof adhering to the core, comprising elongating the core, of acovered core of a given length, applying a force to the coverlongitudinally of the cover during the elongation of the core,continuing the elongation of the core until the cover is free to movethereon, and measuring the amount of elongation ofthe core necessary tofree the cover for movement on the core.

6. A method of testing a covered core, the cover thereof adhering to thecore, comprising elongating the core, of a covered core of a givenlength, applying a force to the cover longitudinally of the cover duringthe elongation of the core, continuing the elongation of the core until'the cover is free to move thereon, holding the core in the elongatedposition, and measuring the amount of elongation of-the core necessaryto free the cover for movement on the core.

of a given length at the ends of the cover, means to cause relativemovement of the units to cause Y the units to elongate the core untilthe .cover is free thereon, and means to measure the amount ofelongation of the corebetween the units and the ends of the cover. I

10. An apparatus for use .in testing the tightness of a cover on acovered core, the cover nor? mally adhering to the core, comprisingunits adapted to grip uncovered ends of a covered core, of a givenlength at the ends of the cover, means to cause relative movement of theunits to cause the units to elongate the core until the cover is freethereon, means cooperating withthe moving means to cause the units tohold the core at the position reached when the cover was freed from thecore, and means to measure the amount 7. An apparatus for use in testingthe tightness of a cover on a covered core, the cover normally adheringto the core, comprising units adapted to grip uncovered ends of acovered core of a given length at the ends of the cover, means to causerelative movement of the units to cause the units to elongate the corewithin the cover thereof, and means to measure the amount of elongationof the core between the units and the ends of the cover.

8. An apparatus for use in testing the tightness of a cover on a coveredcore, the cover normally adhering to thecore, comprising units adaptedto grip uncovered ends of a covered 'core of a given length at the endsof the cover, ,means to cause relative movement of the units to causethe units to elongat the core in the cover thereof, means cooperatingwith'the said moving means to cause the units to hold the core at aselected elongated position, and means to measure the amount ofelongation of the core between the units and the ends of the cover.

9. An apparatus for use in testing the tightness of a cover on a coveredcore, the cover normally adhering to the core, comprising units adaptedto grip uncovered ends of a covered core of elongation of the corebetween the units and the ends of the cover.

11. An apparatus for use in testing the tightness of a cover on acovered core, the cover normally adhering to the core, comprising unitsadapted to grip uncovered ends core of a given length at the ends of thecover, means to support the units at positions spaced a distance equalto the coveredportion of the core, means to cause relative movement ofthe units to cause the units to elongate the covered core, and meansadjacent both units to measure the amount of elongation of the corebetween the units and the ends of the cover.

12. An apparatus for testing a covered core,

the cover thereof adhering'to the core, comprising units adapted to gripuncovered ends of a covered core of a given length, means to support theunits at positions spaced a distance equal to the covered portion of thecore, ,means to cause relative movement of the units to cause the unitsto elongate the covered core, and individual graduated means adjacenteach unit to measure the amount of elongation of'the core relative tothe cover thereon.

CHRISTOPHER J. KROGEL.

of a covered

